The Keysight (Agilent/HP) 8508A Vector Voltmeter is a fully automatic tuned receiver designed for easy and highly sensitive RF voltage and phase measurements. Featuring a narrowband measuring technique, it provides a dynamic range of over 90 dB and a high sensitivity of 10 µV. It can measure the phase difference between two input channels with a resolution of 0.1 degrees across a full ±180-degree range, making it ideal for characterizing electrical length, phase distortion, and impedance.
Specifications
General
| Parameter | Value |
|---|---|
| Interfaces | HP-IB (GPIB) |
| Display | Dual digital numeric displays for amplitude and phase |
| Compatible Input Modules | 85081B High Impedance Input Module, 85082A 50 Ω Input Module |
| Warm-up Time | 30 minutes |
Physical
| Parameter | Value |
|---|---|
| Power Supply | 100 / 120 / 220 / 240 V AC (+5%, -10%), 48 to 440 Hz, 80 VA max |
| Operating Temperature | 0 to 55 °C |
| Dimensions (W×H×D) | 425 mm × 133 mm × 474 mm |
| Weight | 11.5 |
Frequency and Channel Configuration
| Parameter | Value |
|---|---|
| Frequency Range (High Impedance Probe) | 100 kHz to 1 GHz (with HP 85081B input module) |
| Frequency Range (50 Ω) | 300 kHz to 2 GHz (with HP 85082A input module) |
| Number of Channels | 2 (Channel A and Channel B) |
| Frequency Tuning Modes | Automatic (search and lock), Manual (frequency entry) |
Amplitude Measurement Performance
| Parameter | Value |
|---|---|
| Sensitivity | 10 µV |
| Voltage Measurement Range | 10 µV to 1 V rms full scale |
| Amplitude Resolution (dB) | 0.01 dB |
| Amplitude Resolution (Percent) | 0.1% of reading |
Phase Measurement Performance
| Parameter | Value |
|---|---|
| Phase Measurement Range | -180° to +180° |
| Phase Resolution | 0.1° |
RF Input Characteristics
| Parameter | Value |
|---|---|
| Input Impedance (with 85081B) | 100 kΩ nominal shunted by approx. 3 pF |
| Input Impedance (with 85082A) | 50 Ω nominal |
| Input Connector Type (with 85082A) | Type-N female |
Outputs and Auxiliary Interfaces
| Parameter | Value |
|---|---|
| IF Output Frequency | 20 kHz nominal |
| Analog Recorder Outputs | Amplitude: 0 to 1 V, Phase: -1.8 V to +1.8 V |
Environmental and Standards Compliance
| Parameter | Value |
|---|---|
| Storage Temperature Range | -40 °C to +75 °C |
Accuracy
| Parameter | Value |
|---|---|
| Ratio Magnitude Accuracy (100 kHz to 300 MHz) | ±0.2 dB |
| Ratio Magnitude Accuracy (300 MHz to 1 GHz) | ±0.4 dB |
| Ratio Magnitude Accuracy (1 GHz to 2 GHz, with 85082A) | ±0.4 dB |
| Ratio Phase Accuracy (100 kHz to 300 MHz) | ±1.0° |
| Ratio Phase Accuracy (300 MHz to 1 GHz) | ±1.5° |
| Ratio Phase Accuracy (1 GHz to 2 GHz, with 85082A) | ±2.0° |
| Absolute Magnitude Accuracy (100 kHz to 100 MHz) | ±1.0 dB |
| Absolute Magnitude Accuracy (100 MHz to 300 MHz) | ±1.5 dB |
| Absolute Magnitude Accuracy (300 MHz to 1 GHz) | ±2.0 dB |
| Absolute Magnitude Accuracy (1 GHz to 2 GHz) | ±2.5 dB (with 85082A) |
Input Characteristics
| Parameter | Value |
|---|---|
| Maximum Operating Input Level | +16 dBm (2 V peak) |
| Maximum Non-Destructive Input Level | +24 dBm (5 V peak, ±15 V DC) |
| Input SWR (with 85082A) | < 1.15 (300 kHz to 100 MHz), < 1.25 (100 MHz to 1 GHz), < 1.40 (1 GHz to 2 GHz) |
Locking Characteristics
| Parameter | Value |
|---|---|
| Channel A Minimum Locking Level (100 kHz to 300 kHz) | 1.5 mV |
| Channel A Minimum Locking Level (300 kHz to 1 GHz, with 85081B) | 300 µV |
Isolation & Crosstalk
| Parameter | Value |
|---|---|
| Channel-to-Channel Isolation (100 kHz to 500 MHz) | >100 dB |
| Channel-to-Channel Isolation (500 MHz to 1 GHz) | >80 dB |
| Channel-to-Channel Isolation (1 GHz to 2 GHz) | >70 dB |
Outputs
| Parameter | Value |
|---|---|
| Analog Recorder Output Voltage | 0 to ±1 V |
Interfaces & Control
| Parameter | Value |
|---|---|
| HP-IB Interface Functions | SH1, AH1, T6, TE0, L4, LE0, SR1, RL1, PP0, DC1, DT1, C0, E2 |
Measurement Features
| Parameter | Value |
|---|---|
| Phase Zero Range | ±180° |
Technology
Tuned Receiver / Vector Voltmeter
Applications
RF Voltage and Phase Measurements, Electrical Length, Phase Distortion, Impedance Characterization